The objectives of this proposal are to develop the monogamous prairie vole as a novel laboratory animal model for preclinical pain research. Two specific aims are proposed: (1) determine the response of prairie voles to nerve injury using both reflexive withdrawal measures of hypersensitivity and non-reflexive measures of the affective/motivational components of pain, and (2) determine how pair-bonding between prairie voles or disruption of pair bonds in these animals affects pain responses and resolution of pain after nerve injury. Prairie voles are unique among most vertebrate species in that, like humans, they form lifelong monogamous pair bonds with both the male and female undertaking significant roles in raising offspring. Clinically, patients with chronic neuropathic pain that reprt stable and supportive relationships with a partner are shown to have improved treatment outcomes than those without such social enrichment. The mechanisms by which positive social interaction may mitigate pain have not been explored in a preclinical setting, in part due to the lack of similar social interactions between humans and typical laboratory animal models such as mice and rats, or even non-human primates. The prairie vole has been utilized for two decades to understand the neurobiology of pair bond formation and social interaction, and the prominent role of oxytocin, vasopressin, and dopamine in these behaviors are now appreciated. The prairie vole genome has been sequenced and BAC libraries are currently being constructed for design of knockouts or genetic mutants and this species will continue to be developed as an important model species. This provides the pain research community with an opportunity to explore ways in which this species can be utilized to address pain neurobiology, including the influence of human-like social behaviors, which no other species can presently afford. These studies will develop the prairie vole as an important tool for preclinical pain research, as well a advance the understanding of how pain influences social behavior in these animals for the prairie vole research community at large.